#include <stdio.h>

//https://www.nowcoder.com/practice/ae6a21920cac4f9184c8ecfcc87f89b9?tpId=107&&tqId=33404&rp=1&ru=/ta/beginner-programmers&qru=/ta/beginner-programmers/question-ranking

int main() {
    int a = 0;
    int max = 0;
    for (int i = 0; i < 4; i++) {
        scanf("%d", &a);
        max = max < a ? a : max;
    }
    printf("%d", max);
    return 0;
}

